Eren was disguised as a wounded soldier in Marley to make it more believable he started a family with a woman that was already sick and dying so nobody said anything, their was no love in it, it was simply just for a benefit

Soon Eren and the women had you

And soon Zeke, his older half brother got to meet you and as they sat on the bench as Eren held you*

Zeke was tossing up a baseball

Zeke: "So it's yours then?"